The line machinery isn't customized to make nachos or quesadillas
in restaurants. For instance, workers can't melt nacho cheese, so
instead they order the toppings so that the cheese sits right on
top of the beans, which are hot. And the items aren't in any operations
manual. Employees are left to teach each other how to do the
off-menu concoctions, creating an "oral
history," according to Wilson.